Before the season, the December matchup between the Green Bay Packers and the Atlanta Falcons appeared to be a game to circle on the NFL calendar.

Now that the time has come for the teams to meet, it's no longer a marquee pairing. Instead the game on Sunday at Lambeau Field will be between teams that have fallen far short of expectations.

The season has gone so poorly in Green Bay (4-7-1) that the Packers fired longtime coach Mike McCarthy after last Sunday's 20-17 loss at home to the Arizona Cardinals.

Joe Philbin, Green Bay's offensive coordinator and a former head coach of the Miami Dolphins, has taken over from McCarthy as interim head coach.

"I haven't slept very much," Philbin said. "You come back here and you want to be part of the solution. You want to help a guy that's been a great man, he's been a great coach, been a friend, and you feel like you let him down.

"So it's been busy, and I told the team, what he's done here speaks up for itself. You know, I know how he feels (to be fired). I've been through it. It's not fun."

Packers right tackle Bryan Bulaga doesn't expect many drastic modifications to the offense with Philbin in charge.

"I don't think we're going into the offensive meeting room and we're going to change everything about this offense," Bulaga said. "I don't think that's the case. I've known Joe for a long time. I think he's a very good coach. Obviously, he's going to have his own ideas and thoughts as well. There's going to be a different feel to it, I'd imagine."

The Falcons (4-8) are in the midst of a four-game losing streak, but it appears that Atlanta head coach Dan Quinn will not suffer the same fate as McCarthy this season. Falcons owner Arthur Blank recently gave Quinn a vote of confidence.

"I wasn't looking for any of those things in that way, but I definitely appreciated it," Quinn said. "And I recognized that the questions go with the territory when you fail more tests than you pass. Certainly, these two teams, who are strong and proud teams, have had disappointing seasons up to this point."

The quarterback matchup will be in the spotlight during what's expected to be a chilly day.

Green Bay's Aaron Rodgers is not having his best season. He completed 31 of 50 passes for 233 yards in the loss to the Cardinals and broke Bart Starr's franchise-record interception-free streak. Rodgers now has thrown 336 consecutive passes without being picked off and is closing in on Tom Brady's NFL-record 358.

"I think we all share in the responsibility (of McCarthy's firing). That's the toughest part," Rodgers said. "The players are the ones who are playing. Obviously, coaches have responsibility to prepare and teach and demand, but the players on the field are performing and obviously our performance level wasn't such that we could keep Mike in his place."

Falcons quarterback Matt Ryan's numbers seemingly conflict with the team's fate. He has completed 70.9 percent of his passes with 25 touchdowns, five interceptions and a 109.3 rating.

After a three-game winning streak reversed a 1-4 start, Atlanta has failed to reach 20 points in any of its four consecutive losses.

Atlanta ranks last in the NFL in rushing yards and 31st in rushing attempts. That's hardly the sort of balance that Quinn wants, but the Falcons have been hurt by the loss of injured Pro Bowl running back Devonta Freeman.

"Clearly on the last four games is where I felt like we hit a wall," Quinn said.